Latch mechanism



Oct. 25, 1955 J, T. RuDls ET AL 2,721,750

LATCH MECHANISM Filed Jan. 16, 1952 2 Sheets-Sheet l M L" JNVENToRs.-

Frederick J. ooag By JOSG/O/ QUd/'S wml@ MM TORNEI Oct 25, 1955 J. T. RUDls ET AL 2,721,750

LATCH MECHANISM 5 I '$242 SS 182 207 zo; 220a 2 7 224 g JNVENToRs.-

' 'El Frederick J. 5000/ BY J056 /7 7. Bud/'.5

ORNEY United States Patent Oice 2,721,750 Patented Oct. 25, 1955 2,721,750 LATCH MECHANISM loseph T. Rudis, San Diego, and Frederick J. Boody, Burbank, Calif., assignors, by mesne assignments, to General Dynamics Corporation, a corporation of Delaware Application January 16, 1952, Serial No. 266,766

6 Claims. (Cl. 292-139) This invention relates to latch mechanisms and more particularly to ilush type latches.

An object of the present invention is to provide a iiush type latch mechanism having an improved construction adapting it for use both as a restraining member and as a hinge for doors, aircraft engine cowl panels, and like coverings for openings.

Another object of the present invention lies in the provision of an improved latch mechanism wherein its locking bolt is under the control of an operating handle adapted to lie with its outer surface flush with the outer surface of the door or other closure with which it is used, the operating handle normally being maintained in flush position by a iiush mounted manually actuable latching lever carried by the operating handle.

Another object of the present invention resides in providing a iiush type latching device having an improved construction particularly adapting it for use in aircraft where smooth contours are a primary consideration.

Another object of the invention is to provide an irnproved ilush type latching device for use on aircraft for securing access doors, Cowling, inspection hole closures, and the like, which latching device embodies a construction which is extremely reliable and insures against a closure member being inadvertently opened, but which is adapted manually to be readily and easily operated to permit a covering to be opened quickly when such is desired.

A further object of the invention is to provide a unique mounting arrangement for a closure covering utilizing a plurality of latch mechanisms of the above described character for hingedly supporting the closure covering with its exterior surface being flush or in streamlined relationship with the exterior surface of the member which carries the closure covering.

A still further object of the invention is the provision of an improved construction for a latching device embodying a novel locking bolt which is adapted to serve as a hinge member about which a closure covering may be swung.

A further object of the invention is the provision of an improved Hush type latch mechanism which is characterized by its simplicity, its lightness of weight, its eiiiciency, its low cost of manufacture, and its durability.

Other objects and features of the present invention will be readily apparent to those skilled in the art from the following speciiications and appended drawings wherein is illustrated a preferred form of the invention, and in which:

Figure l is a sectional View of a latch constructed in accordance with the present invention, the latch being shown in latched condition. 'i

Figure 2 is a fragmentary view illustrating the bottom of the latch of Figure 1 and showing a portion of the framing structure which carries the latch, and further showing a portion of the cover secured by the latch.

Figure 3 is an end view taken along line III- III of Figure 1.

Figure 4 is an illustration of a door hingedly mounted by a plurality of latches which are constructed in accordance with the present invention.

Figure 5 is a sectional View of a modified form of the latch of this invention.

Figure 6 is a bottom View of the modiiied form of'latch of Figure 5.

Figure 7 is an end view of the latch of Figure 5.

Figure 8 is a sectional view illustrating a further modiiication of the invention.

Figure 9 is a bottom view of the modified latch of Figure 8; and

Figure l0 is an end view of the latch of Figure 8.

Having reference now with greater particularity to the drawings, there is shown in Figures 1 to 3, inclusive, an illustrative embodiment of the latch of the present invention, which is generally designated by the numeral 10. Latch 10 is illustrated as mounted in latching position adjacent a cover, indicated generally at 11, which cover may be an access door, inspection door, cowl panel, or any other like cover which is releasably to be latched. It is understood that cover 11 may be embodied in an airplane, Vehicle, other conveyances or any structure where an openable cover must be used. Cover 11 may be swingably mounted upon a wall, a panel, an engine nacelle, a wing, or any other structure having an opening to be closed.

Cover 11 is designed, when in latched position, to lie in flush relation to a framing structure 13 defining an opening to be covered.

Framing structure 13 is provided with an opening 14 adjacent an edge of cover 11, within which opening the latch 10 is adapted to be operatively supported in a manner to be described.

Latch 10 comprises a generally rectangular frame or supporting bracket 15 having a pair of downwardly depending, laterally spaced ilanges or side walls 16 interconnected at one of their ends 17 and at the top edges thereof by an integral web 18 whose exterior surface is flat or otherwise conforms closely to the exterior surface of cover 11 and framing 13 to lie in ilush relationship therewith. The opposite ends 21 of the flanges 16 are interconnected by an integral end wall 22 having a thickened portion 23 at its lower end with a transverse opening 24 therethrough for a purpose to-be described. A guide block 25 having laterally spaced upstanding iianges 26 is secured to the ends 17 of flanges 16 by a pin 27 which passes through aligned openings in the guide block anges 26 and has its ends fixed, as by peening to the flanges 16. Guide block flanges 26 are provided with aligned bolt receiving openings 28 and the guide block 25 itself has a longitudinal bore 29 which accommodates a bushing 31 serving a purpose to be described. i

Latch frame 15 is xedly secured to framing structure 13 and at the opening 14 therein by bolts 32 and 33, bolt 32 passing through transverse opeening 24 in end wall 22 and being suitably mounted upon opposed structural members 34 of framing structure 13 and bolt 33 passing through openings 28 in anges 26 of guide block 25 and also being suitably mounted upon the spaced structural members 34. n

A latching pin or bolt 37 is reciprocally supported in bushing 31 and is adapted to be extended beyond the end of bushing 31 and into` a bushing 38 carried by a projection 39 of cover 11 and positioned in alignment with bushing 31. A third bushing 41 may be positioned on framing structure 13 in alignment with bushings 31 and 38 to receive the end of bolt 37 and provide support therefor.

An elongated actuator or handle 42 is iitted into the space between flanges 16 of frame 15 and is of a configuration which adapts it to substantially close this space.

The outer surface of actuator 42 when in its closed position vas shown in full lines in Figure 1, is designed to lie in flush relationship to the outer surface of the cover 11. Actuator 42 is preferably mounted near its end l43 Yfor rotative movement on a transverse pivot pin 44 carried by frame iianges 16 adjacent the upper edge o'f end wall 22. Actuator 42 is biased by a torsion spring l45 for opening movement in a counterclockw'ise -direction to an intermediate position projecting above cover 11, which position is shown in Figure l by broken lines and indicated generally by the numeral 46. Torsion spring 45 includes a medial portion 47 which bears against the undersurface of actuator 42 for urging it outwardly, two spaced series of loops 48 encircling a pin 51 carried by frame flanges 16, and two extending ends v52 and .53 which are curved -or bent over the thickened portion '23 vof end wall 22 and bear thereagainst.

Actuation of bolt .37 to and from latched position by .handle 42 is effected through a connection therebetween .afforded by a link 54 having an arm 55 and an arm 56 disposed at an obtuse angle to Veach other. Pivoted connection of the outer end of arm 55 is made to handle 42 by a screw 57 which has the vouter end of its shank 58 threaded and which screw is supported by a pair of laterally spaced depending flanges 59 and 60 provided on .the undersurface of handle 42 at a position displaced from the pivoted end 43 of handle 42. The end of arm 55, as shown in the drawings, lies positioned between depending lugs 59 and .60, and the pivoted connection therebetween is effected by passing screw 57 through .aligned openings in lug 59 and arm 55 and screwing the .threaded end of screw 57 into an opening in the second lug 60, the arm 55 being adapted to rotate upon a smooth surfaced portion .of the shank 58 of screw 57.

Latching bolt .37 is provided at its outer end 61 with a pair vof longitudinally extending projections 62 and 63 between which the outer end of arm 56 of link 54 is .fitted Pivoted connection between link 54 and latching bolt 37 is effected by a pivot pin 64 passed through aligned openings provided in projections 62 and 63 and arm 56.

Actuator .or handle 42 under the bias of torsion spring 45 will be urged normally to occupy intermediate position 46 shown by broken lines in Figure 1, kwherein it may be readily manually grasped for effecting movement of .bolt 37 rectilinearly out of engagement with cover bushing .38 and framing bushing 41 as will be hereinafter further described. To hold handle 42 in closed position, wherein its outer surface conforms to lthe outer surface of framing structure 13 there is provided a release member or trigger lever 65 which is pivotally supported by handle 42. Release member 65 is preferably constructed of sheet metal which is suitably formed to .provide a cover portion 66 which is adapted `to close an access opening 67 afforded in the handle 42. The sheet metal material comprising release member 65 is also .suitably bent to effect a camming portion 68 having a camming or latching face 69. Cover .portion 66 and `.camming portion 68 of release member 65 are interconnected by a flat section 71 which is adapted normally to abut against the under-surface of handle 42 in the closed position of release member 65. Handle 42 has spaced depending lugs 72 and 73 afforded near its free end 74 to which the camming portion 68 of release member 65 is pivotally connectedrby a pivot pin 75. It is noted that pivot pin 75, in the closed position 'of handle 42, is located directly above the pivot pin 64 which connects link 54 and latching bolt 37, that is, both pivot pins -lie .in the same plane normal to handle 42, as viewed in Figure 1.

Camming face 69 is adapted to engage a depending projection or keeper 76 provided by ange connecting web 18 and thereby hold -release member 65 in latched position shown by full lines in Figure 1. Release member 65 .is normally .maintained in its llatched position, by

the biasing force of a torsion spring 77 coiled upon pivot pin 75 and having one end 78 bearing against the under surface of section 71 and its other end 79 hooked about lug 72 and lying in a notch 81 provided in an edge surface of lug 72 to prevent slipping therefrom.

Release member is adapted to be moved from closed, or latched position, to a depressed position, indicated by broken lines in Figure l at 82, in which latter position the camming face 69 will have moved out of yengagement with projection 76. Pivotal movement of release member 65 about its pivot 75 and against the biasing force of spring 77 to free camming face l69 from keeper 76 is accomplished by the application of manual pressure upon the cover portion 66 of release member 65. With camming face 69 disengaged, the biasing force of torsion spring 45 is then available to move handle 42 in a counterclockwise direction to its intermediate position 46, as shown in Figure 1. Manual pressure need be maintained upon cover portion 66 of release member 65 only until handle 42 has moved suiciently under the urging of spring 45 to carry release member 65 beyond the position where camming face 69 could reengage keeper 76. It is understood that the strength of spring is less than that of spring 45 so that the pressure required to overcome the bias of spring 75 to rotate release member 65 will not prevent torsion spring 45 from effecting Athe required counterclockwise movement of handle 42 to its intermediate position 46.

The distance moved by handle 42 under the urging of spring 4'5 is limited and determined by the length afforded link 54 which is pivotally connected to handle 42 and bolt 37. lHandle 42 will rotate on its pivot 44 and the ends of interconnecting link 54 will rotate on pivot screw 57 and pivot pin 64 under the bias of spring 45 but the Vforce exerted by spring -45 through link 54 upon pivot 64 is preferably designed not to be sufficient to Veffect a movement of bolt 37. Thus movement of yhandle 42 from its -closed position to its intermediate position 46 preferably does not result in movement of bolt 37.

To effect retraction of bolt 37 from latching engagement with projection 39 of cover 11, it is necessary manually to grasp handle 42 and move it arcuately in counterclockwise direction from its intermediate position 46 to t-he position shown .by broken lines in Figure 1 and indicated by numeral 83. This manual movement of handle 42 counterclockwise from intermediate position 46 to full open position 83 carries or pulls link 54 with it thereby to apply a withdrawing force to bolt 37 to the pivot connection 64 of link 54 to bolt 37 This results in a rectilinear, withdrawing movement of bolt 37 from locked to .unlocked position to free cover 11 for movement relative to framing structure 13. It is noted that bolt 37 is of elongated cylindrical form having substantial thickness to aord strength thereto, and having its forward end somewhat pointed to enable vit to readily enter bushings 38 .and 41.

Relatching of cover 11 is effected by placing it in .flush position and then manually rotating handle 42 from its open position 78 to its closed position. In this movement earn portion 68 of release member 65 will strike against the edge of web 18 to effect rotative movement of release member 65 against the bias of its spring 77, this positions cam face 69 beneath the upper surface of handle 42. As soon as -handle 42 is in its closed position vspring 77 rotates release member 65 in a clockwise direction to carry cam face 69 into engagement with keeper 76 thereby to latch handle 42 closed.

While latch 10 has been described as mounted on the permanent structure and locking a cover 11 in position by engaging a projection thereof, the invention contemplates supporting the latch on the cover and projecting the bolt 37 into a keeper bushing carried by the permanent structure thereby to secure the cover in place.

The modified vform of latch illustrated in Figures 5 to 7, and indicated generally by the numeral 90, comprises as its essential elements a frame 91, an actuating handle 92, a release member 93 for controlling the movements of the actuating handle 92 and a rectilinearly movable elongated, cylindrical bolt 94.

Frame 91 comprises opposed anges 95 and 96 connected at one of their ends 97 by an integral web 98 and having adjacent their opposite ends 99 a cylindrical spacer 100 which lies disposed in the space between the flanges 95 and 96 and is supported by a bushing 101 which latter member is itself secured to opposed flanges 95 and 96 by peening of its outer ends. Bushing 101 is adapted to accommodate a bolt (not shown) by means of which frame 91 may be mounted either to an appropriate closure cover or upon the permanent structure. Ends 99 of anges 95 and 96 are upwardly directed and serve to mount a pin 102 which rotatably supports the actuating handle 92.

Actuating handle 92 is normally biased for movement to an intermediate position, shown in broken lines in Figure 5 and indicated generally by the numeral 103, by a torsion spring 104 which extends about pivot pin 102 and has one end bearing against theundersurface of handle 92 and its other end engaging the upper surface of spacer 100.

Release member 93 serves to maintain actuating handle 92 in its closed position shown in full lines in Figure 5. Release member 93 embodies a trigger plate 105 having a configuration which adapts it to fill substantially an access opening 106 provided in handle 92. Suitably aixed, as by welding, to the undersurface of trigger plate 105 is a generally U-shaped bracket 107 having opposed legs 108 and 109, through which extends a pin 110 by means of which release member 93 is pivotally supported upon a bracket 111 aiiixed to the undersurface of handle 92. Release member 93 also includes an elongated catch member 112 comprising a nose portion 113 having a platform portion 114 with depending anges 115 and 1.16 and an inclined face 117. Platform portion 114 is at across its upper surface and is adapted to abut against the undersurface of web 98. The engagementv of the Hat upper surface of platform 114 with web 98 prevents the free movement of actuating handle 92 to its intermediate position 103 under the urging of spring 104. Catch member `112 includes rearwardly extending leg portions 118 and 119 spaced below the platform anges 115 and 116 and whose outer ends are pivotally supported by a pin 120 upon the legs 108 and 109 of bracket 107 carried by trigger plate 105. It is noted that pivot pin 120 is located below and to one side of pivot pin 110 about which trigger plate 105 and its bracket 107 pivot as a unit. It is apl parent that as trigger plate 105 and bracket 107 are rotated about pivot 110 pivot pin 120 carried by bracket 107 will 4be moved relative to pivot pin 110 and generally to the left as viewed in Figure 5. Since pivot pin 120 is connected to catch' member 112 this will result in the latter 'also being moved to the left thereby to disengage nose portion 113 from web 98. Catch member 112 is supported and guided in its movements'by a depending flange 121 provided by bracket 111. Flange 121 is slotted as at 122 to accept platform 114. Thus as pivot pin 120 is displaced upon movement of trigger plate 105 and bracket 107, platform 114 will move within slot 122. The slot 122 is of suflicient dimensions that any generally arcuate movement that may be afforded nose portion 113 is readily accommodated.

Bracket 111 which mounts the pivot pin 120 comprises, as best shown in Figure 6, a flat body portion of generally U-shape having spaced legs 123 and 124 disposed on either side of access opening 106, each leg being rigidly secured to the undersurface of handle 92 by rivets 125. Bracket .111 includes spaced lugs 126 land 127 which support pivot pin 110. Slotted ange 121 which guides and supports -noseportion 113 of catch 112 is bent downwardly from the' bight portion 128 of bracket 111. To maintain release member 93 in its closed position there is afforded a torsion spring 129 encircling pivot pin and having one end portion 131 bearing against the undersurface of bracket 107 and its other end portion 132 hooked about lug 126 to engage the undersurface of bracket 111. As shown in Figure 5, the body portion 133 of bracket 107 extends beyond an end of access opening 106 to abut against the undersurface of handle 92 to limit the outward movement of trigger plate 105 to a position wherein its outer surface lies substan-V tially flush with the exterior surface of handle 92.

A guide block 136 having a body portion 137 with a through bore within which is positioned a bushing 138 and having upstanding spaced anges 141 and 142 is carried by frame 91 just below web 98. A suitable pin 143 passing through aligned openings in anges 141 and 142 and having its ends secured to frame flanges 95 and 96 mounts guide block 136 in the required location. Aligned openings 144 are afforded in upstanding flanges 141 and 142 for accommodating a bolt (not shown) for mounting the latch 90 upon a suitable cover or permanent structure.

Guide block 136 with its bushing 138 supports bolt 94 for rectilinear movement. Actuation of bolt 94 is controlled by handle 92 and is effected by interconnecting the inner end of bolt 94 to lugs V145 and 146 provided on handle 92 by means of an angled link member 147. As shown, one end 148 of link 147 is pivotally connected by a pin 151 to rearwardly extending, spaced projections 152 and 153 of bolt 94 and the other end 154 of link 147 is rotatably mounted on a pivot pin 155 carried by handle lugs and 146. Spacers 156 are also positioned on pivot pin 155 on either side of the point of connection of end 154 of link 147 to hold the end 154 generally centrally on pin 155. The operation of latch 90 is similar to that of latch 10 rst hereinbefore described. Actuating handle 92 is adapted to move in a counterclockwise direction to its intermediate position 103 under the urging of its spring 104 when trigger plate 105 and bracket 107 of release member 93 are manually caused to rotate clockwise against the resistance of spring 129 about pivot pin 110 to move catch 112 to disengage its nose portion 113 from web 98. As in the case of latch 10 movement of handle 92 by spring 94 to its intermediate position 103 does not result in any movement of bolt 94 from its latched position shown in full lines in Figure 5, the ends of interconnecting link 147 in this free movement of handle 92 merely rotating about two pivot pins 151 and 155. In its intermediate position 103 handle 92 is adapted to be grasped readily and moved counterclockwise to open position, shown in broken lines in Figure 5 and indicated by the numeral 157. In this latter movement of handle 92, end 154 of link 147 is moved outwardly and to the left thereby applying a pulling force at the pivot pin connection 151 of link 147 to bolt 94 to result in rectilinear movement of bolt 94 within bushing 138 to its unlatching position.

To return bolt 94 to its latched position handle 92 is merely moved in clockwise direction toward frame 91 to apply pressure, through link 147, upon the end of bolt 94 and cause it to move rectilinearly within its bushing 138 to project beyond the end of the bushing. As handle 92 is moved into closed position inclined face 117 rides upon the edge of web 98, to displace catch 112 against the bias of spring 129 and permit the nose portion 113 thereof to clear web 98, As soon as nose portion 113 is clear spring 129 exerts its force to rotate trigger plate 105 and bracket 107 counterclockwise to force catch 112 to the left to position the platform portion 114 thereof beneath web 98 and thereby secure handle 92 in its closed position.

Reference is now made to the form of the invention shown in Figures 8 to 10 which includes the essential elements of the two embodiments previously described. This third modification of the latch of the present invention is indicated in the drawings generally by the numeral and comprises a frame 181formed of two .side wall members 182 and 183 l-hel'd in spaced relation Aby a spacer 184 positioned `between the ends 185 fand 186 of vthe wall members. .A concentric bushing 187 whose outer ends are secured to lthe wall members 182 and 183, tas by peening, mounts spacer .184 yand .is :adapted to accommodate a 'bolt (not shown) which attaches latch .90 to the particular cover which latch 90 is to be used. Aixedto .the opposite ends 1'91 and '192 of wall members 182 `and 183 is a guide member .193 comprising a generally cylindrical Vbody portion 194 bored ito accept a bushing 195 within which is positioned, 4for rectilinear movement, a latching bolt 196. .A protuberance 197 is provided -upon the cylindrical body portion v1.94 and is Iransversely Ibored to permit the passage of a mounting pin 198 whose lopposite ends are suitably fixed to side wall members .182 and 183 thereby to attach guide member 193 to frame 181. A transverse bore 201 is provided in protuberance .197 through Vwhich a bolt (not shown) may be'passed for'mounting latch 90 to its-cover.

An actuating handle 202 comprising a base portion -203 with an 'access opening .204 'and two depending spaced flanges 205 and 206 is pivotally mounted vupon frame 181-by a pin 207 which extends through aligned openings in flanges 205 and 206 and has its ends affixed to side walls 182 .and `183 of frame 181. A torsion spring 208 supported by pin 207 and having end portions 211 and 212 engaging respectively the undersurface `of .handle 202 .and spacer 184 exerts its force to move handle 202 to an intermediate position shown by broken lines in Figure '8 and .identified by lthe numeral 213. To :hold handle 202 in its closed position shown vbyfull lines in Figure 8 there is provided a release member 214. Release member 214 comprises a base por- -tion 215 which conforms in shape to that of access opening 204 .in handle 202 and is adapted to Vsubstantially -ll such opening. Projecting downwardly from base portion 215 are two flanges 216 and 217 each having a notch 218 provided in an edge surface to effect a hook 21'9 having an inclined face 220. Keeper pins 221 and 222 are af`n`xed respectively to side wall members 182 and 183 of frame 181 for cooperation with hooks 219, Athe pins projecting sufficient distance from the wall members to be received within notches 218 of flanges 216 land 217 thereby to latc'h release member 214 .to frame 181. Release member 214 is rotatably supported upon handle 202 by va transverse pivot pin 223 affixed to fhandle .flanges 205 and 206. Pivot pin 223 is located directly above keeper pins 221 and 222 in the same -vertical plane. held in engagement with keeper pins 221 and 222 by .the force of a spring 224 mounted on vpivot pin 223 having one end 225 .bearing against the undersurface of base portion 215 of release member 214 and .its other end .226 vengaging the .undersurface of base 'portion 203 of actuating handle 202. Spring v224 by holding hooks 219 .in engagement with keeper pins 221 and 222 .releasably secures release member ,214 to frame 1'81 and positions the outer surface of base portion 215 of release member 214 substantially .in `flush relationship with the outer `surface of handle 202. To assure Athat this flush relationship is attained, a projection 227 is afforded on base portion 215 of release member 214 which under the urging of spring 224 engages the undersurface of the vhandle 202 in an .area adjacent the access opening 204.

Rectilinear movement of bolt 196 within its bushing 195 on operation of .handle 202 is effected through an angled link 231 having one end v232 pivotally connected iby a pin 233 4to rearwardly extending projections 234 of bolt 196 and having its other end 235 pivotally secured by a pin 236 .to .connecting brackets 237 and 238 movable with :handle 202. .It is noted that cylindrical portion 194 of guide member 193 is cut away as at 239 to permit the rotation of link 231 about i-ts connection to bolt 196. In this rotative movement link 231 is Hooks 219 lare adapted normally to be o adapted to pass between the -ends of keeper pins '221 .and 222 which project from walls 182 and 183 of frame 181. Brackets 237 and 238 are pivotally connected at one of their ends to pivot pin 207 and are supported -on handle 202 by a pin 240 whose ends 'are -suitably rigidly fixed to handle flanges 205 and 206. Spacers 241 and 242 supported respectively on pin 207 and `pin ,240 hold connecting brackets 237 and 238 in'spaced apart relationship. It is apparent that as handle 202 moves, carrying pin 240 with it, there will ybe a pivotal movement of brackets 237 and 238 about pin 207 and displacement of pin 236 which joins the ends Vof the brackets to the end 235 of link 231 thereby shifting vthe position 'of link 231.

The operation of latch 180 is substantially the same as that of latches 10 and 90 previously described. Manual pressure is applied to release member 214 to rotate it about pivot 223 against the bias of spring 224 to disengage hooks 219 from keeper pins 221 and 222 thereby freeing handle 202 from frame 181 and permitting spring 208 to rotate handle 202 counterclockwise toits intermediate position 213. This movement of handle -202 rshifts end 235 of link 231 upwardly and rotates its other end 232 about pin 233 mounted on bolt 196. As in the case of the other latches described this initial operation of handle 202 does no't affect bolt 196, there being no force applied at pin 233 sufficient to shift vbolt 196. To actuate bolt 196 to its unlatched position it is necessary to grasp and move handle 202 arcuately to its full open position shown by broken lines in Figure 8 and indicated by the numeral 243. This movement of handle 202 shifts link 231 to pull bolt 196 to the left to its unlatched position.

In returning handle 202 to its closed position shown in full lines in Figure 8, the inclined faces 220 of hooks 219 ride over keeper pins 221 and 222 until a position is reached wherein the keeper pins 221 and 222 can slide within notches 218 thereby to secure release member 214 in position and latch handle 202 to frame 181.

Thus in each of the latches described the actuating handle is maintained in a latched position by a release member which when operated results in the actuating handle being moved under spring action to a first or intermediate position. This initial movement of the actuating handle has no effect on the latching bolt. In or der to effect rectilinear movement of the latching bolt it is necessary to displace the actuating handle to a second position. In this latter operation the elements interconnecting the handle 'and the latching bolt are moved bodily to apply a withdrawing force to the end of the latching bolt. The latches are readily installed in roperative position by the use of a pair of mounting bolts. Each of these latches may be installed directly on a cover in a suitable opening therein and have its latching bolt cooperate with vmeans on the permanent structure to releasably maintain the cover in closed position, or the latch may be supported upon the permanent structure and have latching engagement with the cover.

As was hereinbefore stated, the latches of the present invention are adapted to serve as hinge means for a cover. Figure 4 illustrates adaptation of the latches to such use. As shown a cover 250 is located within a surrounding framing structure 251 and with its exterior surface in flush relationship to the surface of the wall carrying .the framing structure 251. Four latches are employed with cover 250, these latches could be latches 10, 90 or 180 hereinbefore described. 4Assuming that the latches shown in Figure 4 are of the preferred construction illustrated in Figures 1 to 3, there will be suitably mounted to framing structure 251 one latch at each of the four corners of the cover 250, these latches for the sake of .convenience of description are identified by the numerals 10a, 10b., 10c and 10d. As shown, cover 250 preferably has .four projecting portions 252, 253, 254, and 255, one located rat each of its four corners and each adapted to be lengaged by the cylindrical latching bolt 37 of the particular latch positioned adjacent thereto. Cover 2507wil1 thus be held in required position by the four latching bolts 37. It is noted that the latches a, 10b, 10c and 10d are positioned, a pair adjacent opposite edges of cover 250, and so located that the latching bolt 37 of latch 10a is oppositely disposed to and coaxially aligned with the latching bolt 37 of latch 10b and that the latching bolt 37 of latch 10c is similarly located relative to latching bolt 37 of latch 10d.

Providing a latching engagement, as described, at the four corners of cover 250 will adapt the cover 250 to be swingably moved either about a hinge line 256 passing through cylindrical bolts 37 of the pair of spaced latches 10a and 10b or about a second hinge line 257 extending through the cylindrical bolts 37 of spaced latches 10c and 10d.

To swing door 250 about the hinge line 257 it is necessary merely to depress release members 65 of latches 10a and 10b to freehandles 42 for manual actuation thereof to eiect the withdrawal of bolts 37 from engagement with cover projections 252 and 253. The bolts 37 of the second pair of latches 10c and 10d may then serve as hinges for cover 250 and the cover may then be moved to open position as by means of handholds (not shown) suitably located thereon.

It is apparent, then, that cover 250 may be selectively rotated about either hinge line 256 or hinge line 257 dependent on which pair of latches is maintained in latched position to project the latching bolts 37 thereof to serve as hinges. It is also evident that the cover 250 may be removed completely by disengaging all of the latches.

In some installations it may be more desirable to support the four latches upon the cover itself and in such case the latching bolts will be adapted to project outwardly beyond the edges of the cover to be received within suitable apertures aiforded on the framing structure defining the opening to be covered.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims.

What we claim is:

l. In a latch mechanism, a support member, an actuating handle mounted for pivotal movement on said support member, a latching bolt, means carried by said support member for slidably mounting said latching bolt for rectilinear movement between projected and retracted positions, link means having a pivotal connection to said actuating handle and a pivotal connection to said latching bolt, and spring means for moving said actuating handle from a closed position to an intermediate open position to displace the pivotal connection of said link means to said actuating handle and rotate said link means about its pivotal connection to said latching bolt without movement of the latter from projected position, said actuating handle being movable from its intermediate open position to a second position to transmit a withdrawing force through said link means to said latching bolt to move it to retracted position.

2. In a latch mechanism, a support member, an actuating handle mounted for pivotal movement on said support member, a latching bolt, means carried by said support member for mounting said latching bolt for movement between projected and retracted positions, link means having a pivotal connection to said actuating handle and a pivotal connection to said latching bolt, spring means mounted on said support member and exerting a bias on said actuating handle, movable means carried by said handle and cooperating with said support member for releasably holding said handle in closed position against the bias of said spring means, said movable means adapted when actuated to free said handle for movement by said spring means to an intermediate open position to displace the pivotal connection of said link means to said actuating handle and rotate saidlink means about its pivotal connection to said latching bolt without movement of the latter to its retracted position, said actuating handle being manually movable from its intermediate open position to a second position to displace said link means bodilyl t0 apply a withdrawing force to said latching bolt to move it to retracted position.

3. A latch mechanism comprising support means, an actuating handle mounted for pivotal movement on said support means, a latching bolt, means carried by said support means for slidably mounting said latching bolt for rectilinear movement between projected and retracted positions, link means having a pivotal connection to said actuating handle and a pivotal connection to said latching bolt, spring means exerting its bias upon said actuating handle, means movably mounted on said actuating handle for releasably holding said actuating handle in closed position against the urging of said spring means adapted when actuated to free said actuating handle for movement by said spring meansto an intermediate open position to displace the pivotal connection of said link means to said actuating handle and rotate said link means about its pivotal connection to said latching bolt without movement of the latter to its retracted position, said actuating handle being manually movable from its intermediate open position to a second position to transmit a withdrawing torce through said link means to said latching bolt to move it to retracted position.

4. A latch mechanism comprising a support member, an actuating handle mounted for pivotal movement on said support member, a latching bolt, guide means carried by said support member for slidably mounting said latching bolt for rectilinear movement between projected and retracted positions, link means having a pivotal connection to said actuating handle and a pivotal connection to said latching bolt, spring means mounted on said support member exerting its bias against said actuating handle, means pivotally supported on said actuating handle and cooperating with said support member for releasably securing said handle in closed position, said pivotally supported means being operable to free said handle for movement by said spring means to an intermediate open position to displace the pivotal connection of said link means to said actuating handle and rotate said link means about its pivotal connection to said latching bolt without movement of the latter to its retracted position, said actuating handle being manually movable from its intermediate open position to a second position to apply a withdrawing force through said link means upon said latching bolt to move it to retracted position.

5. A ush-type latch mechanism comprising a frame member having spaced side walls, an actuating handle pivotally mounted adjacent one end of said frame member and adapted when in closed position to span the space between said wall members to close entry therein-between, a latching bolt, guide means carried by said frame member adjacent the opposite end thereof for slidably mounting said latching bolt for rectilinear movement between projected and retracted positions, a link member having one end pivotally connected to said actuating handle and its other end pivotally connected to said latching bolt, release means movably mounted on said actuating handle and cooperating with said trarne member for normally maintaining said actuating handle in closed position, and spring means mounted on said frame member and exerting its bias on movement of said release means to release position to move said actuating handle from its closed position to an intermediate open position to displace bodily the end of said link member connected to said handle and rotate the opposite end of said link member about its connection to said latching bolt Without movement of the latter to its retracted position, said actuating handle being manually movable from its intermediate position to a second position to pull said 11 latching bolt, .by .means of said link member., from .its projected lto its retracted `-position.

6. A flush-type latch mechanism comprising a frame member .having spaced -side walls, an actuating handle .pivotalll mounted adjacent one end -of said frame .member tand adapted when in closed position vto span the space between said wall members to close entry thereinbetween, a latching bolt, guide means carried .by Vsaid frame member adjacentthe opposite -end .thereof for slidably mounting said latching bolt for rectilinear movement between projected and tretracted positions, .a rlink member having one end pivotallyIconnected Vto said -actnating handleand `its other end pivotally connected to said latching bolt, yspring `means `mounted on said frame `member and exerting its bias against said actuating handle,

said handle having an opening in its exterior surface, holding `means pivotally supported by said handle and spring biased normally to vclose said opening, said hoiding means cooperating with said frame member to releasably `secure said actuating handle in its closed position and being operable to `free said .handle for movement by said spring means from its vclosed position to an intermediate -open position to displace bodily the end of said fl (l link member connected to said handle and .to .rotate the'opposite end of said link member about its connec- .tion to said .latching bolt without movement -of the .latter Vto lits retracted position, said actuating .handle 'being manually movable 'from its intermediate position to a second .position to transmit a withdrawing force through said link member to move said latching bolt from its projected vto its retracted position.

References Cited in the file of 'this p'a'tent UNITED STATES PATENTS 510,7'81 Gaedtke Dec. A12, 1.893 761,145 Crandall et al. May 31, S1904 1,024,837 Dupuis Apr. 30, 19'1-2 2,261,146 Dow Nov. 4, 1.9411 2,424,962 Best Aug. 5, 1'947 FOREIGN PATENTS 57,375 Denmark Mar. 11, 1940 981,093 France May 22, l1951 OTHER REFERENCES Automotive and Aviation Industries, May 1, 1944. 

